Eyeglass lens processing system

ABSTRACT

An eyeglass lens processing system includes: input means for inputting frame shape data and layout data; grinding means having holding means for sucking and holding the subject lens at one end of a rotating shaft for nipping and rotating the subject lens, for grinding the subject lens by a grinding wheel; lens conveying means for holding the subject lens placed at a predetermined position and conveying the subject lens to an intended position; amount-of-eccentricity measuring means for detecting a position of an optical center of the subject lens held by the lens conveying means and for obtaining an amount of eccentricity of the optical center of the subject lens with respect to a predetermined reference position; and calculating means for obtaining processing data for the sucked and held subject lens by causing the reference position and the center of the rotating shaft to be aligned with each other by the lens conveying means, on the basis of data on the frame shape, the layout data, and the amount of eccentricity.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an eyeglass lens processingsystem for grinding a peripheral edge of a subject lens.

[0002] Conventionally, in a case where the peripheral edge of a subjectlens is ground, processing is performed after a cup serving as aprocessing jig (a flared suction cup or the like) is attached to theoptical center of the lens. A primary purpose of using the cup is to fixthe lens so that the lens will not move due to the load applied from agrinding wheel during processing. The followings are other purposes.

[0003] When a monofocal lens is processed, a marked point ispreliminarily applied to the optical center of the lens by using a lensmeter, and the cup is attached to the lens through a cup attachingdevice, i.e., a so-called aligner, with that marked point used as areference mark. Subsequently, a cup portion is mounted on a cup holderof a lens chuck shaft provided in a processing apparatus, and the lensis chucked to perform processing. As a result, the processing apparatusis able to effect processing while managing the relationship between therotational center of the lens and the optical center thereof.

[0004] In contrast, to attach the lens directly to the processingapparatus without using the cup, it is necessary to attach the lens byaligning the marked point on the lens and the center of the lens chuckshaft, and it is extremely difficult to enable it in the light of thestructure of the apparatus.

[0005] In recent years, processing centers have been established wherethe lens processing which has been conventionally performed by opticalshops is performed intensively. The processing centers have come toperform large volumes of lens processing in a concentrated manner inresponse to requests from optical shops. In such processing centers,there has been a demand for automation of processing so as to effectprocessing efficiently by saving the trouble of the operator as much aspossible.

[0006] However, as mentioned above, the lens processing requires, theabove-described cup attaching operation as a preliminary step before theprocessing and the cup removing operation as a subsequent step after theprocessing, which has been a difficult factor in realizing theautomation of processing. In addition, since these operations have beenperformed manually by the operator, the operating efficiency has beenpoor.

SUMMARY OF THE INVENTION

[0007] In view of the above-described problems of the conventional art,it is an object of the present invention to provide a processing systemwhich makes it possible to effect processing while managing therelationship between the rotational center and the optical center (andthe angle of the cylinder axis) of the lens during processing withoutusing the cup as a processing jig.

[0008] To overcome the above object, the present invention ischaracterized by having the following configurations.

[0009] (1) An eyeglass lens processing system comprising:

[0010] data input means for inputting processing condition data, theprocessing condition data including frame shape data of an eyeglassframe to which a lens is to be fitted, and layout data for providing alayout of the lens with respect to the frame;

[0011] arithmetic means for obtaining processing data for the lens basedon the data thus inputted;

[0012] lens processing means for grinding a periphery of the lens, thelens processing means including:

[0013] two lens rotating shafts for clamping and rotating the lens;

[0014] holding means for sucking and holding the lens onto at least oneof the lens rotating shafts;

[0015] a rotatable grinding wheel; and

[0016] processing control means for controlling a rotational angle ofthe lens rotating shafts and an axis-to-axis distance between a lensrotation axis and a grinding wheel rotation axis;

[0017] lens conveying means for holding and conveying the lens, whichhas been disposed at a storing position, to an intended position; and

[0018] eccentricity measuring means for obtaining an optical center ofthe lens held by the lens conveying means and obtaining an quantity ofeccentricity of the optical center with respect to a predeterminedreference position,

[0019] wherein the holding means holds the lens so that the lensrotation axis is coincident with the reference position or the opticalcenter, and

[0020] wherein the arithmetic means obtains the processing data based onthe frame shape data, the layout data and the quantity of eccentricityif the lens is held so that the lens rotation axis is coincident withthe reference position, and the arithmatic means obtains the processingdata based on the frame shape data and the layout data if the lens isheld so that the lens rotation axis is coincident with the opticalcenter.

[0021] (2) The eyeglass lens processing system as set forth in (1),further comprising:

[0022] judging means for judging whether or not the quantity ofeccentricity obtained by the eccentricity measuring means falls within apredetermined range.

[0023] (3) The eyeglass lens processing system as set forth in (2),wherein the holding means holds the lens so that the lens rotation axisis coincident with the reference position if the judging means judgesthat the quantity of eccentricity is within the predetermined range, andthe holding means holds the lens so that the lens rotation axis iscoincident with the optical center if the judging means judges that thequantity of eccentricity is outside the predetermined range.

[0024] (4) The eyeglass lens processing system as set forth in (1),further comprising:

[0025] selecting means for selecting a position with which the lensrotation axis is made coincident by the holding means.

[0026] (5) The eyeglass lens processing system as set forth in (4),wherein the selecting means selects a geometric center correspondingposition of the lens corresponding to a geometric center of the eyeglassframe, and the holding means holds the lens so that the lens rotationaxis is coincident with the geometric center corresponding position.

[0027] (6) The eyeglass lens processing system as set forth in (1),further comprising:

[0028] cylinder axis measuring means for measuring a direction of acylinder axis of the lens held by the lens conveying means, wherein thedata input means inputs an angle of the cylinder axis included in aprescription, and the arithmetic means obtains the processing data,taking into account the direction of the cylinder axis and the angle ofthe cylinder axis.

[0029] (7) The eyeglass lens processing system as set forth in (1),wherein the lens conveying means conveys the lens to be positioned ateither of the storing position, a first predetermined position locatedon a measurement axis of the eccentricity measuring means, and a secondpredetermined position located between the lens rotating shafts.

[0030] (8) The eyeglass lens processing system as set forth in (7),wherein the lens conveying means conveys the lens so that the referenceposition is coincident with the measurement axis of the eccentricitymeasuring means when the lens is positioned at the first predeterminedposition, and the reference position or the optical center is coincidentwith the lens rotation axis when the lens is positioned at the secondpredetermined position.

[0031] (9) The eyeglass lens processing system as set forth in (1),wherein the data input means includes eyeglass frame measuring means formeasuring a frame shape of an eyeglass frame or a template thereof.

[0032] (10) An eyeglass lens processing system comprising:

[0033] a data input unit which inputs processing condition data, thedata input unit including an input screen and an input switch, theprocessing condition data including frame shape data of an eyeglassframe to which a lens is to be fitted, and layout data which provide alayout of the lens with respect to the frame;

[0034] an arithmetic unit which obtains processing data for the lensbased on the data thus inputted;

[0035] a lens processing apparatus which grinds a periphery of the lens,the lens processing apparatus including:

[0036] two lens rotating shafts which clamps and rotates the lens;

[0037] a rotatable grinding wheel; and

[0038] a processing control unit which is connected to the arithmeticunit and controls a rotational angle of the lens rotating shafts and anaxis-to-axis distance between a lens rotation axis and a grinding wheelrotation axis;

[0039] a lens conveying apparatus which holds and conveys the lens,which has been disposed at a storing position, to an intended position,the lens conveying apparatus having at least one arm; and

[0040] an eccentricity measuring apparatus which obtains an opticalcenter of the lens held by the arm of the lens conveying apparatus andobtains an quantity of eccentricity of the optical center with respectto a predetermined reference position,

[0041] wherein the lens rotating shafts hold the lens so that the lensrotation axis is coincident with the reference position or the opticalcenter, and

[0042] wherein the arithmetic unit obtains the processing data based onthe frame shape data, the layout data and the quantity of eccentricityif the lens is held so that the lens rotation axis is coincident withthe reference position, and the arithmetic unit obtains the processingdata based on the frame shape data and the layout data if the lens isheld so that the lens rotation axis is coincident with the opticalcenter.

[0043] (11) The eyeglass lens processing system as set forth in (10),wherein the data input unit includes an eyeglass frame measuring unithaving a feeler brought into contact with a groove of the eyeglassframe, and the eyeglass frame measuring unit three-dimensionallymeasures a frame shape of the eyeglass frame based on an amount ofmovement of the feeler.

[0044] (12) The eyeglass lens processing system as set forth in (10),further comprising:

[0045] a control unit connected to the data input unit, the arithmeticunit, the lens processing apparatus, the lens conveying apparatus, andthe eccentricity measuring apparatus.

[0046] (13) The eyeglass lens processing system as set forth in (12),wherein the data inputted by the data input means are inputted into thecontrol unit through a public communication line.

[0047] (14) The eyeglass lens processing system as set forth in (10),wherein at least one of the lens rotating shaft is provided with a holecommunicated through a suction tube to a pump unit to hold the lensunder vacuum.

[0048] (15) The eyeglass lens processing system as set forth in (10),wherein the lens conveying apparatus includes two arms having respectiveholes communicated through a suction tube with a pump unit to hold thelens under vacuum.

[0049] (16) The eyeglass lens processing system as set forth in (10),wherein the eccentricity measuring apparatus includes a grid index of apredetermined pattern, an illuminating unit which illuminates the gridindex and the lens held by the arm of the lens conveying apparatus by asubstantially parallel beam of light, a screen onto which an image ofthe thus illuminated grid pattern is projected, and an image pick-upunit which picks up the thus projected image of the grid pattern.

[0050] The present disclosure relates to the subject matter contained inJapanese patent application No. Hei. 10-275031 (filed on Sep. 29, 1998),which is expressly incorporated herein by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the accompanying drawings:

[0052]FIG. 1 is a diagram illustrating a schematic external view of aneyeglass lens automatic processing system in accordance with the presentinvention;

[0053]FIG. 2 is a diagram explaining the configuration of a lensconveying apparatus;

[0054]FIG. 3 is a diagram explaining the configuration of a distal endportion of a first hand;

[0055]FIG. 4 is a diagram explaining the configuration of a distal endportion of a second hand;

[0056]FIG. 5 is a diagram illustrating a measuring optical system and acontrol system of an eccentricity measuring apparatus;

[0057]FIG. 6 is a diagram explaining a method of detecting the positionof an optical center of a lens LE;

[0058]FIG. 7 is a diagram explaining the configuration of the processingapparatus;

[0059]FIG. 8 is a diagram explaining the configuration of the distal endside of a chuck shaft of the processing apparatus;

[0060]FIG. 9 is a diagram illustrating a system configuration concerningthe order for lenses from an optical shop as well as the acceptance oforders and control processing in the grinding process at a processingcenter where the eyeglass lens automatic processing system in accordancewith the present invention is installed; and

[0061]FIG. 10 is a diagram explaining a method of determining processingdata for correcting a portion of eccentricity of the optical center withrespect to a rotational axis L3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0062] Hereafter, a description will be given of an embodiment of thepresent invention with reference to the drawings. FIG. 1 is a diagramillustrating a schematic external view of the eyeglass lens automaticprocessing system in accordance with the present invention. Theprocessing system includes a processing apparatus 100 for grinding aneyeglass lens; a tray conveying apparatus 500 for conveying trays 400,on each of which a pair of left and right subject lenses are placed, toa predetermined delivering position; a lens conveying apparatus 200 forholding the lens to convey the lens between a tray disposed at thepredetermined delivering position and the processing apparatus 100; andan eccentricity measuring apparatus 300 for detecting the optical centerof the lens held by the conveying apparatus 200 and for measuring itseccentric position. Hereafter, the configurations of the respectiveapparatuses will be described in order.

[0063] <Lens Conveying Apparatus>

[0064] First, the configuration of the conveying apparatus 200 will bedescribed with reference to FIGS. 2 to 4. Reference numeral 201 denotesa conveying base which extends in parallel to the processing apparatus100, the measuring apparatus 300, and the conveying apparatus 500. AnX-moving base 210 which moves in the left-and-right direction (in theX-direction) is mounted on a pair of rails 202 provided on the base 201.A ball screw 204 is connected to a rotating shaft of a motor 203attached to the base 201, and a connecting block 211 fixed to a base 210is threadedly engaged with the screw 204. As the motor 203 is rotativelydriven, the base 210 moves over the base 201 in the X-direction.

[0065] A Y-moving base 220 which moves in the back-and-forth direction(in the Y-direction) along two guide shafts 212 is mounted on the base210. A ball screw 215 connected to a rotating shaft of a motor 214 isthreadedly engaged with a lower portion of the base 220, and the base220 moves in the Y-direction as the motor 214 is rotatively driven. Aholder 222 having a first hand 230 for sucking and holding anunprocessed lens LE and a second hand 240 for sucking and holding aprocessed lens LE′ is mounted on the base 220 in such a manner as to becapable of swiveling, so that the holder 222 is adapted to swivel 180degrees via an unillustrated gear by a motor 221 accommodated in thebase 220. The first hand 230 and the second hand 240 are held by theholder 222 in such a manner as to be movable in the vertical direction(in the Z-direction) by motors 231 and 241, respectively.

[0066] A sucking base 232 is fixed to an end portion of the first hand230, and its distal end portion is formed substantially in a U-shape, asshown in FIG. 3, so as to secure a range of passage of a beam formeasurement by the measuring apparatus 300 which will be describedlater. Further, three suckers 233 projecting downward for sucking thesurface of the lens LE are provided on the sucking base 232 at equalintervals by using as a center a holding reference axis L1 for the X-Ydirection which the first hand 230 has. Each sucker 233 has a suctionhole, and the suction hole communicates with a tube 235 through airpassages formed inside the sucking base 232 and the first hand 230. Thetube 235 is connected to a pump unit 236 which effects the suction anddelivery of air, and as the pump unit 236 is driven and sucks, the lensLE is sucked and held by the three suckers 233, while as the pump unit236 delivers air to the contrary, the suction and holding are canceled.

[0067] Meanwhile, a sucking base 242 is fixed to an end portion of thesecond hand 240, and a flared sucker 243 projecting downward is providedon its distal end side by using as a center a holding reference axis L2for the X-Y direction which the second hand 240 has, as shown in FIG. 4.This sucker 243 is also provided with a suction hole, through which thesucker 243 is connected to a pump unit 246 via a tube 245 in the sameway as the first hand 230, and the suction and holding of the lens LE′by the sucker 243 and its cancellation are effected.

[0068] It should be noted that the mechanism for holding the lenses LEand LE′ may be arranged to nip the peripheral edges of the lenses.

[0069] <Eccentricity Measuring Apparatus>

[0070] A casing 301 of the measuring apparatus 300 has a substantiallyU-shaped side surface, and a measuring optical system and a controlsystem shown in FIG. 5 are disposed in the casing 301. In FIG. 5,reference numeral 302 denotes an illuminating light source; 303, acollimator lens; and 305, a screen plate formed of a semitransparentmaterial (e.g., ground glass). Numeral 304 denotes an index plate with apredetermined pattern formed thereon, and the index plate 304 issupported by a supporting member 304 a embedded in the screen plate 305so as to be located approximately 15 mm above the screen plate 305. Theindex plate 304 in this embodiment is arranged such that a grid index ofblack dots arranged at 0.5 mm-pitch intervals within the range of a20-mm square by using as a center an optical axis L0 of measurement bythe collimator lens 303 is formed on the transparent glass plate. Itshould be noted that this index plate 304 may be disposed on the lightsource 302 side with respect to the lens LE which is mounted as shown inFIG. 5 at the time of measurement. Numeral 307 denotes a CCD camera.

[0071] The lens LE is held by the first hand 230 which theaforementioned conveying apparatus 200 has, and the lens LE is disposedwith its X-Y direction positioned such that the reference axis L1 of thefirst hand 230 becomes aligned with the optical axis L0 of measurement.In addition, the heightwise direction (Z-direction) of the lens LE isset in such a manner as to assume a predetermined heightwise distancewith respect to the index plate 304.

[0072] The illuminating light from the light source 302 is converted toa substantially parallel beam of light by the collimator lens 303, andis projected onto the lens LE. The light beam which passed through thelens LE further illuminates the index plate 304, an image of the gridindex subjected to the prismatic action of the refractive power of thelens LE is projected onto the screen plate 305, and this image is pickedup by the camera 307. An image signal from the camera 307 is inputted toan image processing unit 311, and the processing unit 311 processes theobtained image, detects the position of the index image, and inputs itsdetection signal to a control unit 310. On the basis of the inputteddetection signal, the control unit 310 determines the position of theoptical center and the direction of the cylinder axis of the lens LE.

[0073] A description will be given of a method of determining theposition of the optical center and the direction of the cylinder axis ofthe lens LE on the basis of the image obtained from the camera 307.

[0074] In the case where the lens LE is not mounted, since the gridindex of the index plate 304 is illuminated by the parallel beam oflight, the index image is projected as it is onto the screen plate 305.The control unit 310 stores in advance the coordinate positions of dotimages at this time which are detected by the processing unit 311. Ifthe lens LE is mounted, the dot image located immediately below thevicinity of the optical center of the lens remains at the same positionirrespective of the presence or absence of the lens, but the coordinatepositions of the dots images at portions which are not at the opticalcenter move due to the prismatic action of the lens. Accordingly, todetect the optical center, a change in the coordinate position of eachdot image with the lens LE mounted with respect to the coordinateposition of each dot image with the lens LE removed is examined, and theposition from or toward which the dot images diverge or converge as thecenter is determined. Namely, the center of this divergence orconvergence can be detected as the optical center. In the example shownin FIG. 6, for instance, since the coordinate positions of dot images Pwith the lens LE removed converge at P0 as the center, the coordinateposition of this P0 can be detected as the optical center. Even if theoptical center is located between dots, it suffices if the center ofmovement is determined by interpolating the center of movement on thebasis of the moving directions of the dot images and the amounts oftheir movement.

[0075] According to such a method, the position of the optical centercan be detected accurately irrespective of the powers of the lenses, andthe amount of eccentricity with respect to the optical axis L0 ofmeasurement can be easily transformed into an absolute coordinate.

[0076] In a case where the lens LE has cylindrical power, the dot imagesmove in a direction toward (or away from) a generating line of the lens.Hence, the direction of the cylinder axis can be similarly detected byexamining in which direction the dot images are moving with respect tothe coordinate positions of the dot images with the lens LE removed.

[0077] <Tray Conveying Apparatus>

[0078] In FIG. 1, the conveying apparatus 500 is constituted by a beltconveyor 501, and the trays 400 on the belt conveyor 501 areconsecutively moved in the direction of arrow A. The conveyance of thetrays 400 is stopped at a predetermined position Q1 where the acceptanceand delivery of the lens LE (LE′) are effected by the conveyingapparatus 200. An ID tag 401 on which the work number of the pair ofleft and right lenses has been recorded is attached to each tray 400,and the work number of the ID tag of the tray 400 stopped t the positionQ1 is read by an ID tag reader 502.

[0079] <Processing Apparatus>

[0080] Next, a description will be given of the configuration of theprocessing apparatus 100 with reference to FIGS. 7 and 8. The processingapparatus 100 nips and holds the lens LE by means of an upper chuckshaft 111 and a lower chuck shaft 121 which extend vertically. The upperchuck shaft 111 is moved vertically by a chuck upper portion mechanism110 provided in the center of a sub-base 102, and is rotated by a pulsemotor 113 attached to a holder 112. A lens holder 115 is attached to alower end of the upper chuck shaft 111 (see FIG. 8).

[0081] The lower chuck shaft 121 is rotatably held by a holder 120 fixedto a main base 101, and is rotated by a pulse motor 123 in synchronismwith the upper chuck shaft 111. A sucking member 130 having arubber-made sucking portion 130 a is attached to an upper end of thelower chuck shaft 121 (see FIG. 8). The sucking portion 130 a is formedin a flared shape whose central portion is concave, and a suction holeis provided in a central portion thereof, to which is connected a pumpunit 135 for effecting the suction and delivery of air through an airpassage 131 formed inside the lower chuck shaft 121. After the lens LEis set on the sucking member 130 by the conveying apparatus 200, theupper chuck shaft 111 is lowered, and the sucking operation of the pumpunit 135 is started, thereby making it possible to hold the lens LE sothat the lens LE does not move during processing. When the lens LE isremoved, its suction and holding can be canceled by delivering air tothe sucking member 130.

[0082] The lens LE held by the upper and lower chuck shafts is groundfrom two directions by left and right lens grinding portions 150R and150L each having a group of grinding wheels 151 (a plastic roughgrinding wheel, a finishing grinding wheel having a beveling groove,etc.) on its grinding-wheel rotating shaft. The grinding portions 150Rand 150L are bilaterally symmetrical, and are respectively movedvertically and horizontally by moving mechanisms provided on thesub-base 102.

[0083] In addition, a lens measuring portion 160 is accommodated on afarther side in the center of the sub-base 102, and the measuringoperation of this measuring portion 160, the movement of the grindingportions 150R and 150L, and the angles of rotation of the upper andlower chuck shafts are controlled on the basis of data inputted to thecontrol unit 160 which will be described later. It should be noted thatsince the configuration excluding the lower chuck shaft portion isbasically similar to the one disclosed in Japanese Patent UnexaminedPublication No. 97445/1996 (U.S. Pat. No. 5,803,793) filed by thepresent applicant, reference is had to be made to this publication fordetails.

[0084] Next, the operation of the eyeglass lens automatic processingsystem having the above-described configuration will be described withreference to a system configuration diagram shown in FIG. 9. FIG. 9 is adiagram illustrating the system configuration concerning the order forlenses from an optical shop as well as the acceptance of orders andcontrol processing in the grinding process at the processing centerwhere the processing system in accordance with the present invention isinstalled.

[0085] An ordering terminal 10 and an eyeglasses-frame measuringapparatus 11 are installed in the optical shop, and lens order dataincluding the data on the eyeglasses frame shape measured by theapparatus 11, layout data of the lenses for the eyeglasses frame (thepupillary distance of a client, the distance between geometric centersof the eyeglasses frame, the height of the optical center from thegeometric center, etc.), the lens type, lens prescription data(spherical power, cylindrical power, angle of the cylinder axis), andthe like are inputted online from the ordering terminal 10 to a hostcomputer (hereafter, a host PC) 30 at the processing center through apublic communication line 20.

[0086] At the processing center, a work number is allotted to each of amultiplicity of pieces of order data inputted to the host PC 30, and thework number is registered for the ID tag 401 on each tray 400. A pair ofleft and right lenses LE of the specification read out from the host PC30 is set on each tray 400 on the basis of the work number. At thistime, each lens is set in such a manner that an approximate center ofeach lens is located at a predetermined point on the tray 400.Subsequently, the trays 400 with the lenses LE set thereon areconsecutively placed on the belt conveyor 501 of the conveying apparatus500 (these steps may be performed by the operator, but if an arrangementis adopted in which the steps are automatically performed by a robot,further automation can be realized).

[0087] When the setting of the trays 400 is completed, a control unit510 of the conveying apparatus 500 effects conveyance by operating thebelt conveyor 501, and when the tray 400 is brought to the predeterminedposition Q1 for delivering and receiving the lenses, its movement isstopped. At this time, the work number on the ID tag 401 attached to thetray 400 is read by the reader 502, and its signal is inputted to thehost PC 30. The host PC 30 transmits data concerning lens processingcorresponding to this work number to the processing apparatus 100.

[0088] Further, when the tray 400 is brought to the position Q1, thehost PC 30 transmits an operation command signal to the conveyingapparatus 200. A control unit 250 of the conveying apparatus 200 conveysthe lens LE to a position of measurement by the measuring apparatus 300in the following manner by controlling the driving of each motor. First,the base 210 and the base 220 are moved so that the holding referenceaxis L1 of the first hand 230 is brought to the predetermined point overthe tray 400 where one lens LE is placed. Consequently, the opticalcenter of the lens LE is located in the vicinity of the reference axisL1 within the substantially U-shaped configuration formed in the suckingbase 232. Subsequently, the first hand 230 is lowered to the suckingposition, and as the suction by the pump unit 236 is started, the lensLE (R) for the right eye is sucked and held by the three suckers 233.

[0089] After the lens LE is thus held, the first hand 230 is temporarilyraised, and the first hand 230 together with the holder 222 is thenrotated through 180 degrees to cause the first hand 230 to be orientedon the measuring apparatus 300 side. Subsequently, the base 210 and thebase 220 are moved, the lens LE is conveyed to the position where theholding reference axis L1 of the first hand 230 is aligned with themeasuring optical axis L0 of the measuring apparatus 300, and the lensLE is positioned at a predetermined height. This completes thedisposition of the lens LE at the measuring position.

[0090] When the disposition of the lens LE is completed, a measurementstarting signal is inputted from the host PC 30 to the measuringapparatus 300, and the control unit 310 of the measuring apparatus 300determines the optical center of the lens LE by the above-describedmethod from the image of the index image obtained from the camera 307,thereby obtaining eccentricity information with respect to the measuringoptical axis L0 (namely, this serves as information on the eccentricposition of the first hand 230 with respect to the holding referenceaxis L1). In addition, in a case where the lens LE has cylindricalpower, the angle of the cylinder axis in the state in which the lens LEis held by the first hand 230 is obtained. The information on theeccentricity of the optical center (and the cylinder axial angle data)obtained by the control unit 310 is transmitted to the host PC 30.

[0091] When the measurement by the measuring apparatus 300 is completed,the conveying apparatus 200 conveys the lens LE held by the first hand230 up to the processing apparatus 100. After the lens LE is placed suchthat a rotational axis L3 of the chuck shaft of the processing apparatus100 and the reference axis L1 of the first hand 230 are aligned witheach other, the lens LE is set on the sucking member 130 by the loweringoperation of the first hand 230. Subsequently, the suction on the firsthand 230 side is canceled, and the rear surface side of the lens LE issucked onto the sucking member 130 by the sucking operation of the pumpunit 135, thereby lowering the upper chuck shaft 111. As a result, thelens LE is chucked in the state in which its state at the time ofeccentricity measurement is maintained. The first hand 230 whichcanceled the suction of the lens LE is moved away from the processingapparatus 100.

[0092] It should be noted that when the lens LE is set on the suckingmember 130, if the optical center of the lens LE is offset substantiallyfrom the rotational axis L3 of the chuck shaft, there are cases wherethe accuracy of the processing shape is affected. As a countermeasureagainst this problem, it suffices if the host PC 30 determines whetherthe amount of eccentricity of the optical center obtained from themeasuring apparatus 300 is within a predetermined range (e.g., 10 mm),and if the amount of eccentricity exceeds this range, the lens LE may beset by controlling the movement of the first hand 230 so as to correctthat portion of eccentricity.

[0093] When the chucking of the lens LE is completed, the host PC 30inputs the eccentricity information obtained by the measuring apparatus300 to the processing apparatus 100 to start processing. The controlunit 160 of the processing apparatus 100 determines processing data(this processing data may be obtained on the host PC 30 side) in whichthe portion of eccentricity of the optical center with respect to therotational axis L3 and a portion of offset in the angle of the cylinderaxis are corrected, by incorporating the eccentricity information intothe frame shape data, the layout data, the cylinder axial angle data ofthe lens prescription, and the like which have been inputted earlier.Namely, as shown in FIG. 10, the radial information (rn, 0n) on theframe shape data using the geometric center F₀ of the frame shape as areference is subjected to coordinate transformation using the rotationalcenter G₀ of the lens as a reference on the basis of the coordinateposition of the optical center O₀ determined from the layout data withrespect to the geometric center F₀ as well as the coordinate position ofthe rotational center G₀ of the lens determined from the eccentricityinformation with respect to this optical center O₀, to thereby determinenew radial information (r′n, θ′n). In addition, the angle of thecylinder axis is determined by being transformed into radial informationin which the frame shape is rotated about the optical center O₀ so as tocorrect the offset portion of the detected axial angle with respect tothe axial angle data in the prescription.

[0094] Subsequently, on the basis of the determined processing data, thecontrol unit 160 effects processing while controlling the rotationalangle of the lens LE and the movement (axis-to-axis distance between thechuck shaft and the grinding wheel shaft and the axial position of therotating shaft of the grinding wheel with respect to the lens LE) of thegrinding portions 150R and 150L with respect to the lens LE. As aresult, the lens LE is accurately processed to an intended shape withoutusing a conventional cup as a processing jig.

[0095] It should be noted that, at the time of setting the lens LE atthe position of chucking by the chuck shafts 111 and 121, in addition toeffect the setting as described above, the portion of eccentricity ofthe position of the optical center may be corrected by the control ofX-Y movement of the first hand 230 (namely, such that the rotationalcenter and the optical center of the lens are aligned with each other),or the frame center processing may also be effected such that thegeometric center of the eyeglasses frame is aligned with the rotationalcenter of the lens.

[0096] With respect to the rotational center of the lens, whether thereference axis L1 of the first hand 230 is to be aligned, whether theoptical center of the lens LE is to be aligned, or whether the geometriccenter of the eyeglasses frame is to be aligned may be selected inadvance by the host PC 30. Further, the host PC 30 may make theaforementioned determination and selection on the basis of the frameshape data and the layout data so that the processing shape will becomestable.

[0097] In addition, in a case where a lens with an extremely eccentriclayout or with a narrow vertical width is to be processed, if the lensis set as it is, there are cases where the chuck diameter of theprocessing apparatus 100 (the diameters of the sucking member 130 andthe lens holder 115) projects outside the frame shape, causinginterference in processing. In such a case as well, it suffices if thelens is set in such a manner as to avoid the interference in processingby off setting the position of the lens chuck by controlling the X-Ymovement of the first hand 230. For instance, a selection is made as towhich of the aforementioned positions the lens is to be set.

[0098] In the case where the lens LE is thus set by controlling the X-Ymovement of the first hand 230, the processing data is obtained on thehost PC 30 side, and control of the movement is effected by the host PC30.

[0099] Upon completion of processing of the lens LE, a processingcompletion signal is transmitted to the host PC 30. The host PC 30causes the conveying apparatus 200 to operate again. The processed lensLE′ is conveyed by the second hand 240. The second hand 240 is swiveledto the processing apparatus 100 side, and after the upper chuck shaft111 on the processing apparatus 100 side has been raised, the secondhand 240 moves to the position where the holding reference axis L2 ofthe second hand 240 is aligned with the rotational axis L3 of the chuckshaft. Subsequently, the suction on the lower chuck shaft 121 side iscanceled, and the lens LE′ is sucked and held by the sucker 243 of thesecond hand 240. After the lens LE′ is held, the lens LE′ is conveyed bythe movement in the X-Y-Z direction and the swiveling motion of thesecond hand 240, and is returned to the tray 400.

[0100] When the processing of one lens is finished, the other lens issuccessively conveyed in a similar procedure, and processing is effectedautomatically. Thereafter, the conveyance and processing of the lensplaced on each tray 400 is repeated automatically.

[0101] As described above, in accordance with the present invention, itis possible to effect processing accurately while managing therelationship between the rotational center and the optical center (andthe angle of the cylinder axis) of the lens on the processing apparatusside without using the cup as a processing jig. As a result, the stepsof the operation of inscribing a marked point on the lens by using thelens meter and the attachment and removal of the cup are madeunnecessary, and automatic processing which saves the trouble of theoperator can be effected very efficiently.

What is claimed is:
 1. An eyeglass lens processing system comprising:data input means for inputting processing condition data, the processingcondition data including frame shape data of an eyeglass frame to whicha lens is to be fitted, and layout data for providing a layout of thelens with respect to the frame; arithmetic means for obtainingprocessing data for the lens based on the data thus inputted; lensprocessing means for grinding a periphery of the lens, the lensprocessing means including: two lens rotating shafts for clamping androtating the lens; holding means for sucking and holding the lens ontoat least one of the lens rotating shafts; a rotatable grinding wheel;and processing control means for controlling a rotational angle of thelens rotating shafts and an axis-to-axis distance between a lensrotation axis and a grinding wheel rotation axis; lens conveying meansfor holding and conveying the lens, which has been disposed at a storingposition, to an intended position; and eccentricity measuring means forobtaining an optical center of the lens held by the lens conveying meansand obtaining an quantity of eccentricity of the optical center withrespect to a predetermined reference position, wherein the holding meansholds the lens so that the lens rotation axis is coincident with thereference position or the optical center, and wherein the arithmeticmeans obtains the processing data based on the frame shape data, thelayout data and the quantity of eccentricity if the lens is held so thatthe lens rotation axis is coincident with the reference position, andthe arithmatic means obtains the processing data based on the frameshape data and the layout data if the lens is held so that the lensrotation axis is coincident with the optical center.
 2. The eyeglasslens processing system as set forth in claim 1, further comprising:judging means for judging whether or not the quantity of eccentricityobtained by the eccentricity measuring means falls within apredetermined range.
 3. The eyeglass lens processing system as set forthin claim 2, wherein the holding means holds the lens so that the lensrotation axis is coincident with the reference position if the judgingmeans judges that the quantity of eccentricity is within thepredetermined range, and the holding means holds the lens so that thelens rotation axis is coincident with the optical center if the judgingmeans judges that the quantity of eccentricity is outside thepredetermined range.
 4. The eyeglass lens processing system as set forthin claim 1, further comprising: selecting means for selecting a positionwith which the lens rotation axis is made coincident by the holdingmeans.
 5. The eyeglass lens processing system as set forth in claim 4,wherein the selecting means selects a geometric center correspondingposition of the lens corresponding to a geometric center of the eyeglassframe, and the holding means holds the lens so that the lens rotationaxis is coincident with the geometric center corresponding position. 6.The eyeglass lens processing system as set forth in claim 1, furthercomprising: cylinder axis measuring means for measuring a direction of acylinder axis of the lens held by the lens conveying means, wherein thedata input means inputs an angle of the cylinder axis included in aprescription, and the arithmetic means obtains the processing data,taking into account the direction of the cylinder axis and the angle ofthe cylinder axis.
 7. The eyeglass lens processing system as set forthin claim 1, wherein the lens conveying means conveys the lens to bepositioned at either of the storing position, a first predeterminedposition located on a measurement axis of the eccentricity measuringmeans, and a second predetermined position located between the lensrotating shafts.
 8. The eyeglass lens processing system as set forth inclaim 7, wherein the lens conveying means conveys the lens so that thereference position is coincident with the measurement axis of theeccentricity measuring means when the lens is positioned at the firstpredetermined position, and the reference position or the optical centeris coincident with the lens rotation axis when the lens is positioned atthe second predetermined position.
 9. The eyeglass lens processingsystem as set forth in claim 1, wherein the data input means includeseyeglass frame measuring means for measuring a frame shape of aneyeglass frame or a template thereof.
 10. An eyeglass lens processingsystem comprising: a data input unit which inputs processing conditiondata, the data input unit including an input screen and an input switch,the processing condition data including frame shape data of an eyeglassframe to which a lens is to be fitted, and layout data which provide alayout of the lens with respect to the frame; an arithmetic unit whichobtains processing data for the lens based on the data thus inputted; alens processing apparatus which grinds a periphery of the lens, the lensprocessing apparatus including: two lens rotating shafts which clampsand rotates the lens; a rotatable grinding wheel; and a processingcontrol unit which is connected to the arithmetic unit and controls arotational angle of the lens rotating shafts and an axis-to-axisdistance between a lens rotation axis and a grinding wheel rotationaxis; a lens conveying apparatus which holds and conveys the lens, whichhas been disposed at a storing position, to an intended position, thelens conveying apparatus having at least one arm; and an eccentricitymeasuring apparatus which obtains an optical center of the lens held bythe arm of the lens conveying apparatus and obtains an quantity ofeccentricity of the optical center with respect to a predeterminedreference position, wherein the lens rotating shafts hold the lens sothat the lens rotation axis is coincident with the reference position orthe optical center, and wherein the arithmetic unit obtains theprocessing data based on the frame shape data, the layout data and thequantity of eccentricity if the lens is held so that the lens rotationaxis is coincident with the reference position, and the arithmetic unitobtains the processing data based on the frame shape data and the layoutdata if the lens is held so that the lens rotation axis is coincidentwith the optical center.
 11. The eyeglass lens processing system as setforth in claim 10, wherein the data input unit includes an eyeglassframe measuring unit having a feeler brought into contact with a grooveof the eyeglass frame, and the eyeglass frame measuring unitthree-dimensionally measures a frame shape of the eyeglass frame basedon an amount of movement of the feeler.
 12. The eyeglass lens processingsystem as set forth in claim 10, further comprising: a control unitconnected to the data input unit, the arithmetic unit, the lensprocessing apparatus, the lens conveying apparatus, and the eccentricitymeasuring apparatus.
 13. The eyeglass lens processing system as setforth in claim 12, wherein the data inputted by the data input means areinputted into the control unit through a public communication line. 14.The eyeglass lens processing system as set forth in claim 10, wherein atleast one of the lens rotating shaft is provided with a holecommunicated through a suction tube to a pump unit to hold the lensunder vacuum.
 15. The eyeglass lens processing system as set forth inclaim 10, wherein the lens conveying apparatus includes two arms havingrespective holes communicated through a suction tube with a pump unit tohold the lens under vacuum.
 16. The eyeglass lens processing system asset forth in claim 10, wherein the eccentricity measuring apparatusincludes a grid index of a predetermined pattern, an illuminating unitwhich illuminates the grid index and the lens held by the arm of thelens conveying apparatus by a substantially parallel beam of light, ascreen onto which an image of the thus illuminated grid pattern isprojected, and an image pick-up unit which picks up the thus projectedimage of the grid pattern.